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From Jim Barrows <>
Subject Re: [OT] Are you using Tapestry?
Date Thu, 27 Jan 2005 19:57:34 GMT
On Thu, 27 Jan 2005 20:38:44 +0100, PA <> wrote:
> On Jan 27, 2005, at 20:29, Jim Barrows wrote:
> > Record/Object are sort of the same.
> Hmmm... no. A database row is a database row. Period.
> The rest is algebra.

A record is not necessarily a single database row from a single table.
 Especially in 3NF.

> An object on the other hand is anything your OO implementation language
> of choice allow you to express.
> Certainly "Create Read Update Delete" operations can be applied to
> both, no?

An object, maybe.  Remember an object has the concept of state, and
mutators that change the state.  While this in a simple form is an
update... what if the obejct state has ripple effects?
Specifically.. your writing a publishing system.  As an article to be
published moves through the system it changes states.  When an article
moves to a Complete state, it notifies listeners that the article is
complete and ready to be edited.
Strictly CRUD would look at this as change the Article state in the
database and the next time a "listener" scans the database they'll
pick up the change.  Except that that's not the same as the lisetener
firing off an event, in an asynchronous manner.
I'm not saying this can't be solved ( JMS, RMI, blah blah), just that
it's a place where a CRUD mapping approach falls down.  We don't just
CRUD data in OO, because an object is also the method that act on it.

> Cheers
> --
> PA, onnay equitursay
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James A Barrows

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